Release 0.28.0

[knope-bot]

Important

Merging this pull request will create this release

Breaking Changes

• URL-encode path parameters in generated endpoints (fix!: URL-encode path parameters in generated endpoints #1349)

Fixes

Fix bad code generation

#1360 by @EricAtORS

This fixes:

• missing parenthesis in to_multipart
  Broken UUID multipart template #1338 Bad code generation #1318
• missing imports in the lazy eval in to_multipart:
  Missing lazy_import in model to_multipart() #931 and Missing lazy import in post body to_multipart function #1051

Fix optional bodies

If a body is not required (the default), it will now:

1. Have Unset as part of its type annotation.
2. Default to a value of UNSET
3. Not be included in the request if it is UNSET

Thanks @orelmaliach for the report! Fixes #1354